I may be repeating some things said above- I only skimmed the other responses, so sorry in advance.
Above all, your safety is the most important. If you believe that you will not be safe if you come out to a certain person, do not put yourself in that harmful position. Tell them when you are in a place where they cannot harm you- for example at college, moved out, etc. I know it's really hard to wait, but being safe comes above all.
On top of that, find accepting friends. Social media can be a good place to find fellow trans young people and get support, advice, or just friendship.
I wish you all the best!